The present invention relates generally to racks for supporting self-contained units, and more particularly to rack assemblies of this type which are used to support electronic units such as, for example, electronic internet server units.
In general, racks designed for this purpose include a rectangular frame that extends vertically upwardly from the floor, and the sides of the frame are provided with apertures or openings for receiving screws and the like which are used to mount a plurality of the electronic units in the frame so that they are vertically stacked in close proximity to one another to conserve space. Usually, each electronic unit is self-contained, operates independently of the other units, and requires its own wiring. For example, it is common practice for one company to maintain a large number of internet server units in one room, with each such unit being wired directly to the company which controls the internet server contained within that unit. It will be understood that the number of electronic units that are placed within a rack will vary significantly depending on the vertical height of the rack and the vertical dimensions of the electronic units, but in a representative rack housing internet server units, there may be approximately five units mounted in a single rack.
Since the electronic units will generally house sensitive electronic equipment, it is important that the racks be mounted in place so that the electronics units are not subjected to undue movement or vibration which could render the unit inoperative. Accordingly, most racks of this type are mounted directly to the raised or secondary flooring of a room (e.g. a floor formed by tiles held in place in a metal frame) by foot members that rest on top of the secondary flooring, and long bolts or the like are passed through the foot members and the secondary flooring so that they can be anchored to a primary floor (e.g. concrete flooring) located below the secondary flooring in spaced relation thereto to provide a vertical space for containing wiring, ductwork, and other construction elements, all as well known in the construction industry.
While these known racks are generally secure enough to properly support sensitive electronic units under normal conditions, they are woefully inadequate if there is an abnormal condition, such as an earthquake of a certain size somewhere in the vicinity of the room in which the racks are housed. Under these conditions, the secondary flooring to which the racks are directly connected and which are relatively lightweight and thin in construction, will often buckle or collapse to an extent that the racks secured thereto will also collapse, become twisted, or otherwise be moved to an extent that the sensitive electronic elements supported within the racks will be rendered inoperative. This problem is exacerbated by the fact that these known racks are usually made primarily from aluminum, and at least some of the components of the rack are usually bolted together, all of which creates a somewhat flimsy rack structure.
One effort to solve the problem of properly supporting the racks under these adverse conditions has been to build a specially designed seismic bracing cage that surrounds the rack and adds additional support to the rack, but this is an expensive remedy, both in terms of material and installation costs, and it increases the floor space required to accommodate each rack supported in this manner.
Since it will be understood that racks of this type are being utilized in very large numbers in Silicon Valley and other areas which are prone to experience earthquakes at periodic intervals, and since each of these racks contains a substantial number of independent electronic units upon which many different companies may depend on a daily basis, the seriousness of this problem will be readily apparent.
Additionally, the procedure for installing racks of this general type is relatively complicated. More specifically, in a typical installation, a plurality of the racks are brought to the room in which they are to be installed, and they are temporarily lined up at their expected positions on the secondary flooring so that the secondary flooring can be appropriately marked with indicia showing where all of the connecting bolts will be located. The racks are then moved away, and appropriate floor tiles are removed from the metal frame in which they are mounted so that they can be drilled with holes at the locations indicated by the markings. It is also then necessary to place markings on the concrete primary flooring at each location at which one of the long mounting bolts or all-threads are to be anchored, and since these markings obviously must be coordinated with the holes drilled in the tiles, it is usually necessary to reinstall the tiles and use the holes in the tiles as guides for installing concrete anchors and all-threads in the concrete flooring Then, the floor tiles are put back in place and the racks are bolted to the floor tiles and to the concrete flooring. Thus, this installation procedure is very time consuming, labor intensive and, therefore, expensive.
Accordingly, known racks in which electronic units and the like are mounted suffer serious drawbacks. Most importantly, they are susceptible to major damage in the event of a significant seismic event, and they are difficult and expensive to install. In accordance with the present invention, a rack assembly is provided which overcomes these drawbacks of known constructions.